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millis()
Hier wird die Aktuelle Systemzeit (in Millisekunden) zurückgegeben.

Aufgaben

1. Nutz das Blink Beispiel (Exampels/Basic/Blink) und erweitere es um eine zweite LED.
2. Öffne das BlinkWithout Delay Beispiel (Exampels/Digital/BlinkWithoutDelay) und verstehe das Konzept.
3. Programmiere ein Lauflicht mit 3 LEDs, welches sich von einer zur anderen Seite bewegt.
4. Definiert eine eigene Funktion void blinkLED(int _Pin, int _duration) welche es ermöglicht unterschiedliche LEDs mit unterschiedlichen Geschwindigkeiten blinken zu lassen.

Code Block
languagejava
titleLösung Aufgabe 1
collapsetrue
void setup() {                
  // initialize the digital pin as an output.
  // Pin 13 has an LED connected on most Arduino boards:
  pinMode(13, OUTPUT); 
  pinMode(12, OUTPUT);  
}
 
void loop() {
  digitalWrite(13, HIGH);   // set the LED on
  digitalWrite(12, HIGH);   // set the LED on
  delay(1000);              // wait for a second
  digitalWrite(13, LOW);    // set the LED off
  digitalWrite(12, LOW);    // set the LED off
  delay(1000);              // wait for a second
}
Code Block
languagejava
titleLösung Aufgabe 2
collapsetrue
// constants won't change. Used here to 
// set pin numbers:
const int ledPin =  13;      // the number of the LED pin
 
// Variables will change:
int ledState = LOW;             // ledState used to set the LED
long previousMillis = 0;        // will store last time LED was updated
 
// the follow variables is a long because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long interval = 1000;           // interval at which to blink (milliseconds)
 
void setup() {
  // set the digital pin as output:
  pinMode(ledPin, OUTPUT);      
}
 
void loop()
{
  // here is where you'd put code that needs to be running all the time.
 
  // check to see if it's time to blink the LED; that is, if the 
  // difference between the current time and last time you blinked 
  // the LED is bigger than the interval at which you want to 
  // blink the LED.
  unsigned long currentMillis = millis();
  
  if(currentMillis - previousMillis > interval) {
    // save the last time you blinked the LED 
    previousMillis = currentMillis;   
 
    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW)
      ledState = HIGH;
    else
      ledState = LOW;
 
    // set the LED with the ledState of the variable:
    digitalWrite(ledPin, ledState);
   }
}
Code Block
languagejava
titleLösung Aufgabe 3
collapsetrue
#define LED_ONE 13
#define LED_TWO 12
#define LED_THR 11
 
void setup() 
{                
  pinMode(LED_ONE, OUTPUT); 
  pinMode(LED_TWO, OUTPUT); 
  pinMode(LED_THR, OUTPUT);  
}
 
void loop() 
{
  for(int i=13; i<11; i--)
  {
    digitalWrite(i, HIGH);
    delay(500);
    digitalWrite(i, LOW);
    delay(500);
  }
   
  for(int i=11; i<=13; i++)
  {
    digitalWrite(i, HIGH);
    delay(500);
    digitalWrite(i, LOW);
    delay(500);
  } 
}
Code Block
languagejava
titleLösung Aufgabe 4
collapsetrue
int ledPins[3] = {8,9,10}; // Alle LED Pins in einem Array initialisieren
boolean ledStates[3] = {false, false, false}; // Alle LED Status speichern
long previousMillis[3] = {0,0,0}; // Die Zeiten speichern
 
void setup()
{
  for(int i=0; i<3; i++)
  {
    pinMode(ledPins[i], OUTPUT); // Alle LED Pins sind Output
  }
}
 
void loop()
{
  blinkLED(1, 100);  // Aufrufen unserer Funktion
  blinkLED(2, 1000);
  blinkLED(3, 500);
}
 
void blinkLED(int _Pin, int _duration) // Eigene Funktion
{
  if(millis() - previousMillis[_Pin-1] > _duration) // Ist genug Zeit vergangen?
  {
    previousMillis[_Pin-1] = millis(); // Zeit speichern
    ledStates[_Pin-1] != ledStates[_Pin-1];  // Den LED State umdrehen (wenn AUS dann AN)
    digitalWrite(ledPins[_Pin-1], ledStates[_Pin-1]); // State setzen
  }
}

Weitere Informationen

Getting Started with Arduino – Massimo Banzi (2008)
Arduino – Die Arduino Website. Bitte anschauen…
Mikrocontroller – Was ist ein Mikrokontroller?

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